A novel highly specific biotinylated MAC-ELISA for detection of anti-SARS-CoV-2 nucleocapsid antigen IgM antibodies during the acute phase of COVID-19.

The gold standard for diagnosing COVID-19 in the acute phase is RT-qPCR. However, this molecular technique can yield false-negative results when nasopharyngeal swab collection is not conducted during viremia. To mitigate this challenge, the enzyme-linked immunosorbent assay (ELISA) identifies anti-SARS-CoV-2 IgM antibodies in the initial weeks after symptom onset, facilitating early COVID-19 diagnosis.

Practical use of tobravirus-based vector to produce SARS-CoV-2 antigens in plants.

A plant-based heterologous expression system is an attractive option for recombinant protein production because it is based on a eukaryotic system of high feasibility, and low biological risks. Frequently, binary vector systems are used for transient gene-expression in plants. However, plant virus vector-based systems offer advantages for higher protein yields due to their self-replicating machinery.